Paralidate - Parameters Validator for Koa Router

Paralidate makes a Koa middelware, which validates the request's data include ctx.params and ctx.request.body If the request is valid then Koa continues run the next() middleware. Else, Paralidate stops the request and throw an 400 Http Error.

Paralidate uses Parameter for validating function.

Required

Paralidate will check ctx.params and ctx.request.body, so it assumes you already used koa-router and koa-bodyparser.

• koa-router
• koa-bodyparser

Usage

Install

Install

npm install paralidate --save

# or use yarn

yarn add paralidate

Import

import paralidate from 'paralidate';

or

var paralidate = require('paralidate');

Paralidate options:

const validator = paralidate(rule, opts);

Paralidate is a validator factory. It accepts 2 arguments:

• rule: An object that contains all rules following The Parameter Rules
• opts: Middleware configurations
  • opts.box: ["params" | "box" | callback function ] the place to get data. Default is "params" box also can be a function, that receives ctx as first argument, so you can choose any piece data as you want.
  • opts.outputType: ["simple" | "json" | "complex"] Default is 'simple'
  • opts.errorCode: HTTP Error Code. Default is 409

Validation rules:

There are two ways to declare a rule:

{
  param_name1: 'int', //compact way
  param_name2: 'date',
  param_name3: [1,2,3],
  param_name4: {type: 'enum', values: [1, 2]} // specific way
}

List below presents the equivalence between two ways:

• 'int' => {type: 'int', required: true}
• 'integer' => {type: 'integer', required: true}
• 'number' => {type: 'number', required: true}
• 'date' => {type: 'date', required: true}
• 'dateTime' => {type: 'dateTime', required: true}
• 'id' => {type: 'id', required: true}
• 'boolean' => {type: 'boolean', required: true}
• 'bool' => {type: 'bool', required: true}
• 'string' => {type: 'string', required: true, allowEmpty: false}
• 'email' => {type: 'email', required: true, allowEmpty: false, format: EMAIL_RE}
• 'password' => {type: 'password', required: true, allowEmpty: false, format: PASSWORD_RE, min: 6}
• 'object' => {type: 'object', required: true}
• 'array' => {type: 'array', required: true}
• [1, 2] => {type: 'enum', values: [1, 2]}
• /\d+/ => {type: 'string', required: true, allowEmpty: false, format: /\d+/}

go here for more details.

Example API

This is a very simple Koa Api with koa-router and koa-bodyparser, which we will change it soon!

import Koa from 'koa';
import bodyParser from 'koa-bodyparser';
import Router 'koa-router';

const app = new Koa();
const router = new Router();


router.get('/', function (ctx, next) {
  // ctx.router available
  ctx.body = 'Hello World!';
});

app
  .use(whiteListOrigin)
  .use(bodyParser({
    enableTypes: ['json'],
    extendTypes: ['application/json'],
    onerror: function (err, ctx) {
      ctx.throw('Body parse error', 422);
    }
  }))
  .use(routers)

app.listen(3000, 'localhost');
console.log(`API Server started at http://localhost:3000`);

Validate for all route

To apply a rule for all route, place it after the router middleware:

const validator = paralidate({
  key: {
    type: 'string',
    max: 32
  }
},{
  box: 'params',
  outputType: 'json'
});

app
  .use(bodyParser({
    enableTypes: ['json'],
    extendTypes: ['application/json'],
    onerror: function (err, ctx) {
      ctx.throw('Body parse error', 422);
    }
  }))
  .use(routers)
  .use(validator)

.user(validator) ensures all routers must be included the param key, which is a string of 32 characters.

Validate for specific route

To apply the validator for specific router, place it before the router middelware

const validator = paralidate({
  id: {
    type: 'int',
    min: 1,
    max: 10
  }
}, {
  box: (ctx) => ctx.params,
  outputType: 'json'
});

router.get('/user/:id', validator,function (ctx, next) {
  // ctx.router available
  ctx.body = 'Hello World!';
});

The validator checks ID params in the request, which is integer and between 1 and 10. You also see the opts.box is used as a callback function.